The kinetics of the early stages of electromigration and concurrent temperature induced processes in thin film metallisations studied by means of an in-situ high resolution resistometric technique

Abstract

Compared with traditional test techniques, the in-situ high resolution resistometric technique allows a sensitive monitoring of thin film metallisations submitted to 'realistic' current stress levels and reveals the occurrence of distinct reversible and irreversible processes. A review is provided of the processes observed in metallisations submitted to three regions of current stress: no current stress, low current density stress (j < 0.5 MA/cm(2)) and 'high' current density stress (j > 0.5 MA/cm(2)). Discarding the contributions of the concurrent, temperature induced, masking mechanisms results in an accurate observation of the kinetics of the early stages of electromigration, revealing fundamental features such as incubation time, subsequent linear resistance increase and current and temperature dependence. (C) 1999 Elsevier Science Ltd. All rights reserved.